Question

Main cause of Klinefelter's syndrome is:

• A. Presence of an additional copy of X-chromosome
• B. Absence of one of the X chromosomes
• C. Presence of an additional copy of Y-chromosome
• D. Presence of an extra autosome

Hint:

Remember: Turner's Syndrome is the absence of an X chromosome ($45, XO$), while Klinefelter's is an extra X chromosome ($47, XXY$).

Answer 1

The Correct Option is A

Step 1: Klinefelter's syndrome is a genetic condition caused by a chromosomal aberration in males.
Step 2: It results from the presence of an extra X chromosome, leading to a karyotype of $47, XXY$.
Step 3: This additional X chromosome interferes with male sexual development, often resulting in sterile individuals with some feminine characteristics (e.g., gynecomastia).